You don't need to upload any docs before ITA. However, you need give details of your English exam & ECA.
You will have 60 days after ITA to summit your docs.
Birth certificate isn't mandatory for primary applicant and spouse. Although, for child it is mandatory. In case CIC requests, you should be able to produce it.
I cannot say whether you will be invited before July because no body is aware of the CIC pattern.
But, in case you are invited, you should be able to submit the PR application before the expiry if IELTS i.e., July (what ever date it is).
No it is not valid. You need new PCC from India and it is also needed for your spouse.
No need for PCC from Canada. In case CIC needs, you will be requested later i.e., after submission of PR application.
It can for sure be a problem. The other way should be fine but then as per LMIA if your salary is more, then it will be problem. Actually, the issue is with your employer. He should be paying you as per the promise he made in LMIA.
My CIC Status
31 JAN received ITA
02 MAR application submitted
02 MAR AOR
02 MAR eligibility review in progress
CHANGES
08 MAR A Background check - Not needed at this time --> Not Started
24 MAR A Background check - Not Started --> In Progress
24 MAR Review of Medical results - Not needed at...
Final line in ECAS
We received your application for permanent residence on January 6, 2015. - March 12th
We started processing your application on April 21, 2015. - April 24th
Medical results have been received. - March 27th
A decision has been made on your application. The office will...